‘Abbott Elementary,’ ‘It’s Always Sunny in Philadelphia’ Set Crossover Episode Hollywood Reporter‘Abbott Elementary’ Sets Crossover Episode With ‘It’s Always Sunny in Philadelphia’ VarietyIt’s Always Sunny Takes a Field Trip to Abbott Elementary Vulture"Abbott Elementary," "It's Always Sunny in Philadelphia" tease crossover episode on social media CBS Philly‘Abbott Elementary’ To Cross Over With ‘It’s Always Sunny In Philadelphia’ In Season 4 Deadline